Why when I press the momentary switch does the collector LED stay on? I'm using a 330 resistor for the collector, 1k for the base, and feeding 5v into the circuit. (Iv tried flipping the transistor to see if I had it backwards). The goal is to press the switch and only have the emitter LED on

 

Why when I press the momentary switch does the collector LED stay on?

I have no idea, but if you post a schematic of your circuit I might be able to help.

 

I'm completely new to electronics, but I tried to make a schematic for you. I hope its right

 

The problem is that, when the transistor is turned on (saturated) the collector and emitter voltages are nearly the same, so both LEDs have the same voltage and both light.
To get only the emitter LED to light when the transistor is on, add a standard diode (1N4148 or similar) in series with the collector LED.
You may have to reduce the value of the collector resistor to get the desired LED current.

Below is an alternate circuit that performs the same function.
D1 is on when the transistor is on, and D3 is on when the transistor is off.

 

1). I made an error on my schematic by drawing 2 voltage sources. Their is only 1 power source
2). That diode made a significant difference. The collector led has a very faint light now. I suppose I'll have to mess with the resistances to get it completely off? With that being said is their a rule of thumb when trying to get a transistor in a saturated state? What should the voltage difference be for e<b>c?
3). Thank you for your help

 

is their a rule of thumb when trying to get a transistor in a saturated state?

Yes.
It's not the voltage that is used to determine saturation, it's the base current.
Typically the rule-of-thumb is to have the base current be at least 10% of the collector current (forced Beta of 10) for good saturation.

 

This circuit will eliminate a couple of Rs, and produce only pA in the off LED.




Suffers from brightness dropping when both LEDs on. That could be fixed
by leaving one on all the time with fixed current, and switching the other on
with same valued current limit R. Both LEDs on have identical current/brightness.

2N7000 very useful in your toolboox, basically a usefull 100mA range type of
part. Cheapo as well.

If your switch is left open should add a R to ground at MOSFET gate, say 10K,
to make sure it is not floating, eg. turn on due to leakage, induced noise.

In this example switch pressed, only drain LED on, D2, switch off both on.

Regards, Dana.

 

See